World’s Largest Carbon Sequestration Project Approved

15 October 2006

by Jack Rosebro

The two phases of the Mongstad CCS project. Click to enlarge.

Marking the removal of the final bureaucratic barrier to the construction of the world’s largest full-scale CO2 capture-and-storage (CCS) facility, Norway’s Ministry of the Environment has issued a carbon dioxide emission permit to Norwegian energy company Statoil ASA in conjunction with its planned co-generation plant in Mongstad.

Statoil is taking a phased approach to the project. The initial carbon capture capacity will be about 100,000 tonnes per year starting in 2010, and Statoil will decide in 2012 whether or not to invest in a larger capture facility for Phase 2. If realized, Phase 2 would be fully operational by the end of 2014 with a capacity of more than 1.3 million tonnes of CO2 per year—the world’s largest CCS project of its kind.

Statoil plans to test several technological solutions will be tested in parallel in the first phase of the project with an eye to developing solutions of “broad international relevance and not...project-specific to Norway.”

A technology company responsible for various aspects of the further development of the carbon capture technology is to be set up at Mongstad. The government will invite interested parties to consider part ownership, while Statoil will assume 20% per cent ownership from the start.

2010 is also the year in which Statoil hopes to have reduced carbon dioxide emissions from its operations by about one-third compared with projected 2010 business-as-usual (BAU) emissions. Reduction measures in addition to the Mongstad will include:

Statoil’s three-pronged CO2 reduction strategy. Click to enlarge.

Continued injection of carbon dioxide into buried saline aquifers at the Sleipner West and Snøhvit fields;

Increased energy efficiency at all levels of operation; and

Powering the Troll oil platform with hydroelectric power and natural gas.

Fuelled by surplus gas from the refinery and natural gas from Troll in the North Sea, the CHP plant will provide 350 MW of heat for use in the refinery and 280 MW of electricity. Of that 280 MW, the refinery will use about 60 MW, 40 MW will go to Gjøa, and 180 MW will flow back to power Troll.

Technical concept of the CHP plant. Click to enlarge.

The annual output of the CHP plant will correspond to 2.3 terawatt-hours (TWh), equivalent to two per cent of overall Norwegian electricity generation in a year with normal precipitation. Dong Energy, a Danish energy consortium, will manage the plant.

The co-generation plant will operate at a very high energy efficiency, in the longer term up to 80%. By comparison, traditional gas-fired power plants have an energy efficiency of approximately 58-59%, according to the Ministry of the Environment.

Norway’s Ministry of Oil and Energy is expected to sink about US$22 million into the project.

Statoil said that in relation to the project, “emissions of nitrogen oxides (NOx) from Mongstad are not expected to increase significantly compared with current levels,” and that “only marginal increases are expected in the emissions of sulphur dioxide (SO2), methane (CH4) and volatile organic compounds (VOCs).”

The site of the Mongstad CHP plant. Click to enlarge.

Although CO2 sequestration is still experimental, Statoil has been burying about a million tons of CO2 per year at its Sleipner gas field in the North Sea since the mid-1990s.

In 2005, the Fluor Corporation conducted a CO2 capture study at Mongstad. Their proposed solution would utilize proprietary Fluor-developed carbon capture technology to capture 85% of carbon dioxide produced by Statoil’s planned co-generation plant. The technology, which involves the capture of acid gases in an oxidizing environment, would be implemented in a purpose-built CO2 capture plant that would be built next to the new gas-fired co-generation plant.